Immunological mechanisms have been inplicated in the pathogenesis of human periodontal diseases. The histopathological works suggested that periodonatal lesions might be induced by the immunoregulatory imbalance of T cells which have been recognized to play a central role in the immunoregulatory network at both local and systemic levels. In our previous study, the autologous mixed-lymphocyte reaction (AMLR), which is suggested as a possible indicator of immunoregulation in inflammatory diseases, of peripheral blood lymphocytes has been demonstrated to be depressed in some (39%) adult periodontitis patients (low-AMLR patients). We also demonstrated a lower percentage of CD45RA positive cells in CD4-positive cells (CD4^+CD45RA^+T cells) of peripheral blood lympho-cytes only in the low-AMLR patients but noto the normal-AMLR patients nor healthy control subjects. In the present study, the phenotypic alterations of the CD45 antigens (CD45RA and CD45RO) on CD4^+T cells in the inflamed gingiv
… Morea and peripheral blood lymphocytes from the patients with adult periodontitis were examined in relation to AMLR responses. The flowcytometric analysis of T cell fraction in the inflamed gingiva revealed a relatively lower percentage of CD4^+CD45RA^+CD45RO^-T cells and a higher percentage of CD4^+45RA^-CD45RO^+T cells than those in the peripheral blood, suggesting naive CD4^+T cells in the inflamed gingiva might be actively differentiating into memory cell populations by the continuous stimulation of the local periodontopathic antigens. However, no significant correlation were observed between the alteration of these T cell subsets in the inflamed gingiva and AMLR responses nor the phenotypic alteration in the CD4^+T cell subset of the peripheral blood lymphocytes from the individual subject. The CD4^+CD45RA^-CD45RO^- and CD4^+CD45RA^+CD45RO^+T cell subsets were also found in the inflamed gingiva from the periodontitis patients, although the functional characteristics of these T cell subsets has not been reported. These results might reflect changes in regulatory T cell function induced by development of periodontal diseases.1.臨床的に成人性歯周炎と分類される患者群(被験30名)の中に,末梢血リンパ球のAMLRの低下がみられる患者群(13名;43%)が存在し,これらの患者群でのAMLRの低下は末梢血T細胞サブポピュレーションのCD4^+CD45RA^+CD45RO^-細胞率と関連することが強く示唆れた。2.AMLR値の低下が観察された患者群と,観察されなかった患者群との間で,年齢および臨床的パラメーターに関して統計学的な有意差は認められなかった。3.歯周炎病巣歯肉組織中のCD4^+T細胞サブポピュレーションの解析では,末梢血と比較してCD45RA^+CD45RO^-細胞率が低くCD45RA^-CD45RO^+細胞率が高いことが明らかとなり,歯周炎病巣歯肉局所でナイーブT細胞→メモリーT細胞へのT細胞サブポピュレーションの機能的なシフトが惹起されている可能性が示唆された。しかし,AMLRとの有意の関連性は認められなかった。4.歯周炎病巣歯肉組織では,末梢血中ではほとんど認められないCD4^+CD45RA^-CD45RO^-T細胞あるいはCD4^+CD45RA^+CD45RO^+T細胞が存在することが明らかとなった。5.歯周炎病巣歯肉組織中で特に高いCD4^+CD45RA^-CD45RO^-T細胞率を示す患者群ではいずれも低いAMLR値を示したことから,病巣局所でのこのT細胞サブポピュレーションと末梢血リンパ球のAMLRの反応性が関連する可能性が示唆された。 Less